Gmax is no longer supported by Autodesk

But you can download the files from here.

Gmax version 1.2 installer.

Gmax 1.2 help file installer.

gmax 1.2 tutorials.

The registration process takes you to TurboSquid screens that look like they work.
I did eventually get the registration email from them. but their backup strategy is to use a fixed key they provide on their website. If you don't want to participate in their information harvesting, you can just use this key:

6EC1D06D0852ABCAC41062700C1874FCBC321E48DE971F88899F5A65D3

Just paste it into the dialog when you're asked for it..

Tutorials

For each tutorial, download, unzip and play the video. It should play with sound.

Gmax basic GUI

Create and modify objects

Select and Move objects.

Work with parametric modifiers.

New tutorials as of 11 December 2005.

Example Scenes file. Unzip to gmax\Scenes\

Example maps file. Unzip to gmax\Maps\

Build a table.

Texture a table.

Cameras and Lights.

enjoy